Various electrical devices (including, but not limited to cell phones, PDA's, laptops, tools, medical equipment, et.) can be powered by being placed on top of a charging plate. The charging plate then determines the type and amount of power required and then supplies power to the electrical device, which can, among other things, recharge the batteries of the device.
A first advantage of using a charging plate is that the device can be re-charged or powered without using cords. The user thereby avoids the problem of having to connect the device to a standard plug-in-the-wall power cord.
A second advantage of charging plates is that the electrical device to be powered can be placed on top of the charging plate in any position or orientation. This makes the charging plate very convenient for a user for several reasons. For example, users can simply place a cell phone to be re-charged anywhere on the charging plate and it starts charging. As such, the user does not need to orient the device in any specific direction or location.
A third advantage of charging plates is that they can be used for powering a plurality of devices at the same time. This is particularly advantageous in that it avoids the “Christmas Tree” tangle of power cords typically found when re-charging or powering a number of devices on a desk or countertop. Instead, using a charging pad, each of these devices can be placed next to one another on the same charging pad and they will each receive the proper amount of power.
There are two main types of charging pads: inductive (i.e.: magnetic) coupling charging pads and direct contact charging pads.
A main disadvantage of charging pads has been their cost. Current Charging pads have also been thick due to the need to contain all the electronics necessary to run the pad inside the device. As a consequence, it has been difficult to integrate existing charging pads into common items such as car dashboards, desks, countertops, floor tiles, etc. An inductive charger is also inherently less desirable because of the large amounts of EMI generated as a consequence of running large coils of wire at high power. Because these AC waves are used to power the devices in question, they inherently become EMI which becomes extremely difficult to effectively shield from other nearby devices (computers, radios, televisions, etc.)